The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingIf your vehicle needs to be
towed
If towing is necessary, we
recommend having your
vehicle towed by your
Toyota dealer or commercial
towing service, using a
wheel-lift type truck or flatbed
truck.
Use a safety chain system
for all towing, and abide by
all state/provincial and local
laws.
Situations when it is necessary
to contact d ...
Trailer towing tips
Your vehicle will handle differently when towing a trailer. Help to avoid
an accident, death or serious injury, keep the following in mind when
towing:
Speed limits for towing a trailer vary by state or province. Do not
exceed the posted towing speed limit.
Toyota recommends that the vehic ...
On-vehicle inspection
Check front seat side airbag assembly (vehicle not involved in
collision)
Perform a diagnostic system check (see page rs-
49).
With the front seat side airbag installed on the
vehicle, perform a visual check. If any of the defects
mentioned below are present, replace the fron ...